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How Computers Work: fun facts and quiz
The essentials in 7 ideas, with fun facts, an illustrated story and a quiz to see how much you know.
The essentials
Binary
Computers store everything as 0s and 1s, called bits. Eight bits make a byte, enough to store one letter like “A”.
Key fact
With 8 bits you can count from 0 to 255.
The Processor
The processor, or CPU, is the computer’s brain. It follows instructions one tiny step at a time, billions of times a second.
Key fact
A 3 GHz processor ticks 3 billion times a second.
Memory & Storage
RAM is short-term memory: fast, but wiped when the power goes off. Storage, like an SSD, keeps your files even when the computer is off.
Key fact
RAM stands for Random Access Memory.
Input & Output
Computers take input, process it and give output. Keyboards, mice and microphones are input; screens, speakers and printers are output.
Key fact
A touchscreen is both an input and an output.
Transistors
Transistors are tiny electronic switches that flick on and off to represent 1s and 0s. A modern chip packs billions of them.
Key fact
The first transistor was built at Bell Labs in 1947.
The Operating System
The operating system, like Windows, macOS, Android or iOS, runs the show: it shares the processor and memory between apps and talks to the hardware.
Key fact
Android is built on Linux.
Moore’s Law
In 1965, Gordon Moore noticed that the number of transistors on a chip kept doubling, later put at about every two years. The trend held for decades.
Key fact
Moore’s law is an observation, not a law of physics.
Fun facts
The word “bit” is short for “binary digit”.
A processor runs so hot that, without its cooler, it would overheat and shut itself down within seconds.
The first hard drive, IBM’s RAMAC of 1956, weighed about a tonne and held less than 5 MB.
The first computer mouse, built for Douglas Engelbart in 1964, was a wooden box on two metal wheels.
The word “transistor” blends “transfer” and “resistor”.
Windows was nearly called “Interface Manager”, until marketing staff pushed for a friendlier name.
Today’s transistors are so small that over a thousand could sit side by side across the width of a human hair.
Story: The Christmas Switch
The Christmas Switch
December 1947, Bell Labs. John Bardeen and Walter Brattain press gold foil onto a crystal of germanium. It boosts a signal: the first transistor.
Their boss, William Shockley, is furious to be left out. Over New Year, alone in a hotel room, he designs a better one.
The three shared the 1956 Nobel Prize in Physics, but never worked as a team again. Every chip today holds billions of their switches.
True or false?
Tap your answer to see if you got it, and why.
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Question 1 of 10
A single bit can only be 0 or 1.
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True. Two states: off or on, 0 or 1.
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Question 2 of 10
CPU stands for Central Processing Unit.
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True. It’s the part that carries out the instructions.
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Question 3 of 10
RAM keeps your files after you switch the computer off.
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False. RAM is wiped without power. Files live in storage.
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Question 4 of 10
A keyboard is an input device.
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True. It sends your keystrokes into the computer.
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Question 5 of 10
A transistor works like a tiny switch.
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True. On or off: a 1 or a 0.
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Question 6 of 10
Android is an operating system.
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True. So are iOS, Windows, macOS and Linux.
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Question 7 of 10
Moore’s law is a law of physics.
Show the answer
False. It’s an observed trend in how chips improved.
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Question 8 of 10
Binary uses ten different digits.
Show the answer
False. Binary uses just two: 0 and 1. Our everyday decimal system uses ten.
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Question 9 of 10
A processor can only do one calculation per second.
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False. Modern processors do billions of operations a second.
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Question 10 of 10
An SSD keeps its data without power.
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True. That’s what makes it storage rather than memory.
Keep going in the app
KnowSoda learns what you know and brings back what you’re about to forget. How Computers Work has 6 more ideas at the Advanced and Expert levels.
Sources
- Computer History Museum — timeline of computing and the transistor
- Khan Academy — Computers and the Internet
- Intel — Moore’s Law
- Encyclopaedia Britannica — CPU, RAM, operating system
- Computer History Museum — Grace Hopper; the first computer bug
- Encyclopaedia Britannica — logic gate, cache memory, compiler
- Computer History Museum — Grace Hopper
